Customizable 3D Printed Furniture

Hi there,

Thanks for stopping by. In this Instructable I am going to go through a system of 3D printed joints that I designed to build furniture. I am going to go through how I built a sofa table but I think this system could build a lot of different things.

The goal for me was to build this table as cheaply and simply as possible. I used mostly standard pieces I could get from my hardware store and I think you could find at most hardware stores.

The parts were designed to remove the hard wood working part of building furniture. Everywhere you would need to make a joint you just use a set of printed parts.

A warning up front: This furniture is still going to be held together with 3D printed parts so likely will not bear much weight. Use your best judgement when determining if this is right for you.

Materials

• Dowels (I used 6-72” dowels and 4-48” dowels)
• M3x18 Bolts (I used black oxide hex cap screws. I got a pack of 100 and used about 50)
• M3 Nuts (I got 1 pack of 100. I ended up using about 50 for my table)
• #8 Brass finish screws
• Filament (I’ll get into specifics in a bit)
• Parts - They vary by what your are building, I’ll cover what you need in a bit.
• Stain
• Spray Sealer
• Stain Rags
• Sand paper
• 100 grit
• 220 grit

Tools

• Ender 3 Pro 3D printer
• Hand Saw
• Miter Box
• Clamp
• Wrench
• Circular saw*
• Edge guide*
• Screw Driver
• Drill*
• Measuring tape

*Optional/not always needed

Lets go over the whole point before we get into specific examples.

I designed this system to be flexible and to use standard materials. Notability the structure of the piece is build using 1” dowels, and the parts are held together with M3 nuts and bolts. For a top I initially planed to use a handy-panel (a precut piece of ply wood) but ended up using an edge glued board from my hardware store. The edge glued board looked a bit nicer as it has some good grain patterns.

As I said before, these pieces replace the hard part of building furniture, making joints. Everywhere 2 or 4 dowels meet you use a set of 3D printed parts. Each set consists of 3 printed pieces, a top, bottom, and a retaining ring. In my table I only use corner pieces as I am building a rectangular table. But if you were to build something more complicated you could also use some 3-way connectors, they connect a vertical dowel to 3 horizontal dowels. Or if you are using a span longer than the dowels you have access to I have also printed straight connectors.

I have also designed 2 version of each part, a standard connect used everywhere except the top right under the table top. The top version of each part has a shortened vertical portion so that the table top sits much closer to the top dowel. This makes it easier to connect the table top to the top dowel using some u-brackets designed for #8 finish screws. (I am sorry to use 2 different types of hardware)

The first thing to do with this system is to figure out what you want to build. I am building a sofa table so I took overall measurements of the space I had.

I wanted a table that was 6’ long, 10” wide, and 31” tall. Because I am just using a basic rectangular table I am only using the corner pieces. I’ll go into some other options in the next step. But for now lets continue.

I have highlighted the joints I need to make in red in the drawing. At each of these points I will need a set of printed pieces. On the corners in the middle the connectors are the same for the top and bottom. However on the top of the frame I need the “_top” version of the parts so that the u-brackets can connect to the table top.

Knowing the overall dimensions of the space I was able to make a cuts list of dowels I needed and a list of the parts to print (those are in the next step).

To determine the length of the dowels I needed. I subtracted 2” from the width and length dimensions (so the frame sits under the table not flush with it). I then subtracted 2.5” from the remaining length, this is the size of the brackets (1” for each vertical dowel and 0.25” for the walls around the dowel on either side).

For the vertical dowels I am using a 0.5” edge glued board. I know I want the top of the table to sit at 31” so the vertical dowels just need to be 31” - the table top height or 0.5” = 30.5”

Vertical: 31” - 0.5” = 30.5”

Long sides: 72” - 2” = 70” -> 70” - 2.5” = 67.5”

Short sides: 10” - 2” = 8” -> 8” - 2.5” = 5.5”

Cut list

• 4 at 30.5” (vertical)
• 4 at 67.5” (long sides)
• 4 at 5.5” (short sides)

I’ve included a few other drawings of tables that you could make with this system as well. Again modify it to suit your needs.

This was the longest step for me. I need the list of parts below and printing each slowly to ensure good quality meant taking the time I needed.

I printed all the parts for my table using black PLA, but if I were to build another table I would use PETG. The Ender 3 handles PETG really well, and the extra strength would be beneficial in this application. I ended up using about 700g of filament for my table.

I should also tell you that some of my initial parts cracked after I assembled the table, the retaining rings were the worst, with almost all of them snapping clean through. I made several design changes, specifically adding fillets on the connectors and gusseting the retaining rings. On test parts clamped onto a spare piece of dowel, I haven’t seen any cracking or stress show up in the parts and they have been under minor load for about 3 months at the time of writing.

PARTS

Parts for my table:

• 4 top corner brackets
• 12 standard corner brackets
• 8 retaining rings
• 4 table top brackets
• 4 feet

A quick note on the hardware here, each joint uses nut and bolt pairs. On every joint you will need one pair for the retaining ring. You will also need the additional number below for each joint (these excluded the retaining ring)

Corner: 5 pairs

Straight: 4 pairs

3-Way: 8 pairs

I cut each piece on my cut list using a hand saw and miter box. This came in handy to make sure each cut was square.

I then test fit the parts on the dowels and sanded as need to make sure the pieces fit on easily (Some placed that worked better than others)

Finish is optional. I decided to finishing all of the pieces of this table with 2 coats of stain. I just followed the steps on the container.

I then applied 3 coats of spray on finish for the legs and 2 coats of wipe on finish for the top sanding between each coat. Again I just followed the direction on the cans.

Make sure to stain and finish in a well ventilated area! I did this on my patio over a drop cloth.

Note: Finish will absorb into the wood and potentially change the final diameter of the dowel. If you plan on finishing make sure to fit a part on the finished dowel before printing all the parts. Scale the parts accordingly.

With all the parts stained and all the pieces printed it was time to assemble the whole thing. This was fairly straight forward as I had already done most of the hard work by this point.

I assembled the legs first marketing sure to measure to ensure the lower brackets were all at the same height. I put the short pieces in first to make the two end frames. With the end frames together I put the long sides in to make a whole frame.

To attach the top I placed the top top side down on my floor and set the frame on it upside down. I then measured out where to put the brackets and drilled pilot holes and put in the #8 screws.

And with that the table is done. Just flip it back over and put it in place.

Once in place I added the feet on the bottom of the dowels.

I now have a fantastic table.

I hope that you find this useful and can build the custom furniture piece that you need.

Again please use your judgment to determine if this system will work for you.

Go forth and make stuff!

If you make something with this system of parts add it as a make here, or tag me on instagram @TinyBoatProductions or on twitter @TeenyBoat.